a. Field of the Invention
The instant invention is directed toward an electrode catheter and a method for using the electrode catheter for tissue ablation. In particular, the electrode catheter of the present invention may comprise one or more electro-mechanical sensors such as a piezoelectric sensor for assessing catheter contact with a moving surface (e.g., the heart wall) for ablation procedures.
b. Background Art
It is well known that benefits may be gained by forming lesions in tissue if the depth and location of the lesions being formed can be controlled. In particular, it can be desirable to elevate tissue temperature to around 50° C. until lesions are formed via coagulation necrosis, which changes the electrical properties of the tissue. For example, lesions may be formed at specific locations in cardiac tissue via coagulation necrosis to lessen or eliminate undesirable atrial fibrillations.
Several difficulties may be encountered, however, when attempting to form lesions at specific locations using some existing ablation electrodes. One such difficulty encountered with existing ablation electrodes is how to assess tissue contact. Electrode-tissue contact is not readily determined using conventional fluoroscopy techniques. Instead, the physician determines electrode-tissue contact based on his/her experience using the electrode catheter. Such experience only comes when time, and may be quickly lost if the physician does not use the electrode catheter on a regular basis. In addition, when forming lesions in a heart, the beating of the heart further complicates matters, making it difficult to assess and maintain sufficient contact pressure between the electrode and the tissue for a sufficient length of time to form a desired lesion. If the contact between the catheter and the tissue cannot be properly maintained, a quality lesion is unlikely to be formed.